Systems, Components, and Combinations Thereof for Pen-Type Injection Devices

This application is a division of U.S. Nonprovisional patent application Ser. No. 17/213,777, filed Mar. 26, 2021, now U.S. Pat. No. 12,350,476, which claims priority under 35 USC § 119(e) from U.S. Provisional Patent Applications No. 63/001,122 filed on Mar. 27, 2020, the content of which (including all attachments filed therewith) is hereby incorporated by reference in its entirety.

The disclosure relates generally to a multiple use pen-type injection device. More particularly, the present disclosure relates to driver components, systems and drive methods that facilitate improved dose setting, correcting, and/or dispensing in a multiple use pen-type injection device. In this regard, present disclosure is applicable to pen-type injection devices disclosed for example in U.S. Pat. Nos. 9,295,782; 9,757,525; 9,421,334; and 10,357,614, the disclosures of which are incorporated herein by reference in their entirety.

Various conventional pen-type injection device are known in the art of medication injection devices. These conventional devices sometimes include features for enabling a user to correct a dose that has been set too large, which may be referred to as “dial back”. Another feature that may be provided by some of the conventional devices is the ability to control a last dose of a medication cartridge such that a user cannot set a dose greater than the remaining amount of medication in the cartridge. This feature is sometimes referred to as last dose control or last dose management. Both of these features are desired by users of such pen devices; however, conventional devices may not satisfactorily meet these needs. Many conventional devices may provide one of these features, but not both. Further, many of the conventional devices require additional steps for performing dial back, which are cumbersome and not intuitive to the user.

In addition, conventional pen injection devices commonly include components or mechanism that provide audible and/or tactile signaling and/or feedback during some or all phases of pen operation by the user. Accordingly, many convention injection devices utilize mechanisms, to provide audible and/or tactile feedback during dose setting and/or dose correcting and/or injection.

Thus, there is a need in the art to provide improved functionality of dose setting, dose correcting, dose injecting, last dose control mechanisms, and audible and/or tactile feedback mechanisms, implemented together, individually, or in any combination in a medication injection pen.

Exemplary embodiments of the present disclosure address at least the above problems and/or disadvantages and provide at least the advantages described below.

In accordance with an exemplary embodiment of the present disclosure, a medication injection pen includes a housing and a dose set knob rotatable with respect to the housing. A brake assembly is disposed in the housing has a ratchet member. A driver includes at least one external tooth engaging the ratchet member. The engagement between the ratchet member and the at least one external tooth substantially prevents the driver from rotating with respect to the dose set knob during dose setting and dose correcting. The engagement between the ratchet member and the at least one external tooth allows the driver to rotate with the dose set knob during an injection.

Other exemplary embodiments of the present disclosure, provide various driver systems and mechanisms, each of which can be implemented in medication injection pens as disclosed herein.

Yet other exemplary embodiments of the present disclosure, provide an example of a last dose management system and components, which can be implemented in medication injection pens as disclosed herein including any of the disclosed driver systems and mechanisms.

Yet further exemplary embodiments of the present disclosure, provide an example of an audible and/or tactile feedback mechanisms and components, which can be implemented in medication injection pens as disclosed herein including any of the disclosed driver systems and mechanisms, and/or last dose management system and components.

An exemplary implementation of an embodiments of the present disclosure provides a medication injection pen, comprising: a cartridge housing which houses a medication cartridge; a housing connected to said cartridge housing; a dose set knob rotatable with respect to said housing; a dose stop member to prevent the setting of a dose that is larger than the remaining amount of medication in the cartridge; and a driver, wherein during dose setting and dose correcting, said driver does not rotate with said dose set knob, and said dose stop member rotates relative to said dose set knob, and during an injection, said driver moves into locking engagement with said dose set knob to allow said driver to rotate with said dose set knob, and said dose stop member does not rotate relative to said dose set knob.

An exemplary medication injection pen may further comprise a ratchet disk, said driver rotatably locked to said ratchet disk; and a brake member, wherein said ratchet disc comprises first teeth including first sloped surfaces and first non-sloped surfaces, and said brake member comprises second teeth includes second sloped surfaces and second non-sloped surfaces, during dose setting and dose correcting, said first teeth engage said second teeth to substantially prevent said driver from rotating with said dose set knob, and during an injection, said driver moves into locking engagement with said dose set knob thereby overcoming friction between said first sloped surfaces and said second sloped surfaces to allow said driver to rotate with said dose set knob.

In an exemplary implementation of a medication injection pen, a spring member biases said ratchet member toward said brake member. In another exemplary implementation of a medication injection pen, during said injection, said ratchet disk rotates with said driver and moves against said spring member as said first sloped surfaces ride over said second slope surfaces of said brake member. In yet another exemplary implementation, during said injection, after rotating to a dose increment, said ratchet disk moves into a positions with respect to said brake member where at least one of said first teeth move into a base of next of said second teeth.

In an exemplary embodiment, the medication injection pen can further comprise a brake member; and a ratchet member rotatably locked to said brake member, wherein said ratchet member comprises first teeth including first sloped surfaces and first non-sloped surfaces, and said driver comprises second teeth includes second sloped surfaces and second non-sloped surfaces, during dose setting and dose correcting, said first teeth engage said second teeth to substantially prevent said driver from rotating with said dose set knob, and during an injection, said driver moves into locking engagement with said dose set knob thereby overcoming friction between said first sloped surfaces and said second sloped surfaces to allow said driver to rotate with said dose set knob. In an exemplary implementation, a spring member biases said ratchet member toward said driver. In yet another exemplary implementation, during said injection, said driver rotates forcing said ratchet member to move axially as said first sloped surfaces ride over said second slope surfaces. In still another exemplary implementation, during said injection, after rotating to a dose increment, said ratchet member moves into a positions with respect to said driver where at least one of said first teeth move into a base of next of said second teeth. In still another exemplary implementation, said second teeth are spaced to correspond with the rotation of one dose of medicament. And, in still another exemplary implementation, said ratchet member is a ratchet disc, with an opening configured to receive said driver therethrough.

According to an exemplary embodiment of the disclosure, medication injection pen according can further comprise: a brake member; and a ratchet member comprising ratchet arms, said ratchet member is rotatably locked to said brake member, wherein said driver comprises inward facing ratchet teeth, and said ratchet arms radiate outward toward said inward facing ratchet teeth of said driver, during dose setting and dose correcting, said ratchet arms engage said ratchet teeth to substantially prevent said driver from rotating with said dose set knob, and during an injection, said driver moves into locking engagement with said dose set knob thereby forcing said ratchet arms to flex inward as said ratchet teeth slide past said ratchet arms to allow said driver to rotate with said dose set knob.

In an exemplary implementation, during said injection, after rotating to a dose increment, said ratchet arms move into a base of next of said ratchet teeth. In another exemplary implementation, said ratchet teeth are spaced to correspond with the rotation of one dose of medicament.

According to an exemplary embodiment of the disclosure, medication injection pen according can further comprise: a brake member; and a ratchet member comprising outward facing ratchet teeth, said ratchet member is rotatably locked to said brake member, wherein said driver comprises ratchet arms, and said ratchet arms radiate inward toward said outward facing ratchet teeth, during dose setting and dose correcting, said ratchet arms engage said ratchet teeth to substantially prevent said driver from rotating with said dose set knob, and during an injection, said driver moves into locking engagement with said dose set knob thereby forcing said ratchet arms to flex outward as said ratchet arms slide past said ratchet teeth to allow said driver to rotate with said dose set knob.

In an exemplary implementation, during said injection, after rotating to a dose increment, said ratchet arms move into a base of next of said ratchet teeth. In another exemplary implementation, said ratchet teeth are spaced to correspond with the rotation of one dose of medicament.

According to an exemplary embodiment of the disclosure, medication injection pen according can further comprise: a brake member; and a ratchet member comprising a plate having parabolic waves facing outward toward said brake member, said ratchet member is rotatably locked to said brake member, wherein said driver comprises ratchet teeth including sloped surfaces and non-sloped surfaces, and during an injection, said driver moves into locking engagement with said dose set knob thereby forcing said waves of said ratchet plate to flex to allow said ratchet teeth to rotate past said ratchet plate to allow said driver to rotate with said dose set knob. In an exemplary implementation, during said injection, after rotating to a dose increment, said ratchet teeth move into a wall of next plate cavity. In another exemplary implementation, said ratchet teeth are spaced to correspond with the rotation of one dose of medicament.

According to an exemplary embodiment of the disclosure, medication injection pen according can further comprise: a brake member comprising inward facing ratchet teeth including sloped surfaces and non-sloped surfaces; and wherein said driver comprises flexible ratchet arms that radiate outward toward said inward facing ratchet teeth of said brake member, and during an injection, said driver moves into locking engagement with said dose set knob thereby forcing said flexible ratchet arms to flex inward to slide over said sloped surfaces of said ratchet teeth to allow said driver to rotate with said dose set knob.

In an exemplary implementation, during said injection, after rotating to a dose increment, said ratchet arms move into a base of said ratchet teeth. In another exemplary implementation, said ratchet teeth are spaced to correspond with the rotation of one dose of medicament.

According to an exemplary embodiment of the disclosure, medication injection pen according can further comprise: a brake member rotationally locked to said housing; and a coil spring positioned around said driver, said coil spring is rotationally locked to said brake member and wherein, said coil spring grips said diver prevent preventing said driver from rotating during dose setting by tightening of said coil spring, and during an injection said driver moves into locking engagement with said dose set knob whereby rotation of said driver causes said coil spring to unwind allowing said driver to rotate with said dose set knob.

According to an exemplary embodiment of the disclosure, medication injection pen according can further comprise: a brake member rotationally locked to said housing; and at least one leaf spring rotationally locked to said brake member and positioned radially with respect to said driver, wherein said leaf spring grips said diver prevent preventing said driver from rotating during dose setting by increased tension of said leaf spring, and during an injection said driver moves into locking engagement with said dose set knob whereby rotation of said driver causes said leaf spring to loosen said tension relieving said grip and allowing said driver to rotate with said dose set knob.

According to an exemplary embodiment of the disclosure, medication injection pen according can further comprise: a lead screw including flexible ratchet arms; and a brake member rotationally fixing said lead screw to said housing, wherein said driver comprises inward facing ratchet teeth including sloped surfaces and non-sloped surfaces, said flexible ratchet arms radiate outward toward said inward facing ratchet teeth of said driver, and during an injection, said driver moves into locking engagement with said dose set knob forcing said flexible ratchet arms of said leadscrew to flex inward as they slide over said sloped surfaces of said ratchet teeth to allow said driver to rotate with said dose set knob.

In an exemplary implementation, during said injection, after rotating to a dose increment, said flexible ratchet arms move into a base of said ratchet teeth. In another exemplary implementation, said ratchet teeth are spaced to correspond with the rotation of one dose of medicament.

Additional objects, advantages and salient features of exemplary embodiments of the disclosure, in any combination of features disclosed in exemplary embodiments and implementations described herein, will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with annexed drawings, discloses exemplary embodiments of the disclosure.

Throughout the drawings, like reference numerals and like labels will be understood to refer to like elements, features and structures.

The matters exemplified in this description are provided to assist in a comprehensive understanding of exemplary embodiments of the disclosure with reference to the accompanying drawing figures. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the exemplary embodiments described herein can be made without departing from the scope and spirit of the claimed disclosure. Also, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

is a perspective view of an injection penaccording to exemplary embodiments of the present disclosure described in more detail in the context of exemplary implementation shown in. Also, an injection penaccording to exemplary embodiments of the present disclosure can implement any one of the braking systems which can comprise combinations of various components described in more detail with reference to. Likewise, an injection penaccording to exemplary embodiments of the present disclosure can implement audible and/or tactile signaling and/or feedback components/system as disclosed in detail subsequently herein with reference to, for example in combination with any of the disclosed braking systems.

As shown in, the injection penincludes a pen upper body or housing, which houses a plurality of dose setting and injection components. The upper bodyis connected to a cartridge housing, which houses a medication cartridge, as shown in. The injection penmay also include a lower pen cap (not shown) to cover the cartridgeand cartridge housingwhen the injection penis not in use. As shown, the injection penincludes a dose set knob (DSK)that includes a knob-like portionthat is rotated by a user to set a desired dose. The dose set knobalso includes a plurality of numerals, as shown in, corresponding to a number of dosage units that is visible through a windowprovided on the upper body, as shown in. A user rotates the dose set knobuntil the desired dose is visible in the window. The upper pen bodymay include an arrow or other indicatorto precisely indicate the set dose. Once the desired dose is set, a user presses the buttonuntil the set dosage amount is completely injected.

A push buttonis provided at a proximal end, closest to a user and farthest from a needle (not shown), of the upper pen body, as shown in. The push buttonpreferably comprises an annular bead or rimthat engages with a corresponding annular grooveprovided on the internal surface of the knob-like portionof the dose set knob. The annular rim/groove connection is preferably a friction fit that maintains the push buttonin a biased position on the dose set knobunder the force of a button spring, but allows the push buttonto be pushed into the dose set knobfor injecting a set dose. As shown in, the groovein the knob-like portionof the dose set knobextends axially to allow the push buttonto be pushed into the dose set knobduring an injection. The interior of the buttonaccommodates a setback bearing insertthat rests on an internal surface at a proximal end of the setback member. As shown in, the bearing inserthas an annular rimreceived by an annular groove() adjacent a proximal endof the setback member. The push buttonis designed to rotate freely on the setback bearing insert.

The setback memberis a cylindrical member, as shown in, coaxial with and surrounded by the dose set knob. The setback memberis provided co-axially around a driver, as shown in, that is rotatably fixed to the setback memberand axially movable relative to the setback member. The driverco-axially surrounds a lead screw, as shown in. The setback memberincludes a set of keysextending inwardly from an inner surfaceat a distal endthat engage slotsextending axially on an outer surfaceof the driverto rotatably lock the driverto the setback member. The driverhas threadson a portion of an inner surfacethereof at a distal end of the driver, as shown in. The driverco-axially surrounds a lead screw, which includes a plurality of thread segmentsdisposed along substantially an entire axial length of the lead screw, as shown in. The plurality of thread segmentsare oppositely disposed with flattened portionsbeing disposed therebetween. A flangeis disposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The driver internal threadsare in threaded engagement with the external lead screw threadsprovided on the lead screw. As described further below, due to its threaded engagement with the driver, the lead screwis moved into the cartridgeduring injection to press on a stopperprovided inside the cartridgeto expel a dose of medication. A flexible spacer, such as for example a wave clipas shown in, can be provided between a distal end of a brake memberand a proximal end of the cartridgeto bias the cartridgein a distal direction to substantially prevent movement of the cartridgeduring injection, and thus ensure that an accurate dose is injected.

The brake memberis disposed in the pen upper body, as shown in. The brake memberis a substantially cylindrical member having a substantially planar basefrom which a wallextends axially outwardly. An openingin the basereceives the lead screw. A spring memberis disposed on an inner surfaceof the base of the brake member. A ratchet diskis disposed on the spring member. The ratchet diskis preferably circular with an openingtherein to receive the lead screw. A pair of keysextend outwardly from the ratchet diskto engage the slotsin the brake member. The slotssubstantially prevent rotational movement of the ratchet disk, while allowing axial movement of the ratchet disk. A plurality of teethextend upwardly from an upper surfaceof the ratchet disk. Each toothhas a sloped surfaceforming an obtuse angle with the upper surfaceand a stopping surfacedisposed substantially perpendicularly to the upper surface.

To set a dose using the injection pen device of the first exemplary embodiment, a user rotates the knob-like portionof the dose set knobrelative to the pen upper body. The outer surface of the dose set knobincludes a thread, as best shown in, that is in threaded engagement with a plurality of threadsprovided on an internal surfaceof the upper pen body, as shown in. Accordingly, as the dose set knobis rotated relative to the upper pen body, the dose set knobscrews or advances a distance out of the upper pen body. The dose set knobincludes an annular shoulder or rimon the interior surface thereof near the proximal end, as shown in. The annular shoulderengages with an enlarged portion or headof the setback member, as shown in. The annular shoulderof the dose set knobpreferably comprises a series of teeth or ridgesthat engage with a plurality of similarly shaped teeth or ridgesprovided on the enlarged headof the setback member. During dose setting, the dose set knobis free to rotate with respect to the setback memberin both a clockwise and counter-clockwise direction. As this occurs, the plurality of teeth or ridgesof the dose set knobslip past the teethprovided on the enlarged head portionof the setback member, thus providing a tactile signal or clicking noise indicating the setting of a dose unit. As further described below, the dose set knobis enabled to rotate relative to the setback memberduring setting due to a one-way ratchet that prevents the setback memberfrom rotating together with the dose set knobin the setting direction.

Rotation of the dose set knobin the dose setting direction is not transferred to the setback memberdue to the one-way ratchet between the driverand the ratchet disk, as shown in. The setback membernear its distal end includes a pair of keys, as shown in. The pair of keysengages respective slotsin the driver, as shown in. The keysand slotsrotationally lock the setback memberand the drivertogether while allowing for axial movement of the setback member. A flangedisposed at a distal end of the driverhas a plurality of teethdisposed on a lower surface thereof. The driver teethhave sloped surfacesand stopping surfaces, as shown in. The stopping surfacesof the driver teethengage the stopping surfacesof the ratchet disk teeth, thereby preventing rotation of the driver. The spring memberbiases the ratchet diskinto engagement with the driver flange to facilitate preventing rotation of the driver. Accordingly, preventing the driverfrom rotating also prevents the setback memberfrom rotating. As the dose set knobis rotated out of the pen upper bodyduring dose setting, the engagement between the enlarged head portionof the setback memberand the shoulderof the dose set knobcauses the setback memberto move axially as the keysslide within the driver slots. As noted above, the dose set knob teethslip past the setback member teethduring dose setting to provide a clicking noise to indicate to the user that a dose is being set.

To correct a set dose that may have been set too high, the user rotates back the dose set knobin the opposite direction. Rotation of the dose set knobin this direction is not transferred to the setback memberdue to the one-way ratchet between the driver(to which the setback memberis rotationally fixed) and the ratchet disk, as shown in. The friction between the teethandof the dose set knoband the setback memberis not large enough to overcome the friction between the driver flangeand the spring-biased ratchet disk. Thus, the dose set knobcan be rotated back to correct a set dose without causing rotation of the setback memberin this direction, although the setback memberwill move axially due to the engagement of the setback member keysin the slots. Accordingly, the dose set knob teethslip past the setback member teeth, which is prevented from rotating, to provide a clicking noise during dialing back of the dose, just as during normal dose setting.

As the dose set knobscrews or advances axially out of the upper bodyduring the setting of a dose, the setback memberis also caused to move axially out of the body a corresponding distance. This axial movement is caused by the engagement between the annular shoulderon the dose set knobpushing against the enlarged head portionof the setback memberduring its movement out of the pen upper body. Once a desired dose is set, the user pushes the push buttonthat is coupled to the setback bearing insertthat is axially connected to the setback member. Under the force applied by the user pressing the push button, the setback memberis moved into a locking or meshing engagement with the dose set knobvia a meshing of the respective teeth or ridgesandprovided on the setback memberand the dose set knob, respectively. As the user continues to press the push button, the dose set knobis caused to rotate and screw back down into the pen upper bodyvia the thread engagement between the threadon the dose set knoband the threadin the pen upper body. Rotation of the dose set knobis then transferred to the setback memberdue to their locking or meshed engagement. The force of the user pressing the buttonis enough to overcome the friction between the disk ratchetand the driver flange, and as a result, the setback memberis enabled to rotate in this direction.

Rotation of the setback member, as allowed during injection, is then transferred to the driver, which is rotatably fixed to the setback membervia a key groove connection provided between the driverand the setback member. As shown in, the internal surfaceof the setback memberhas inwardly extending keysthat engage axially extending slotsin the driver, as shown in shown in. The setback memberpreferably includes two oppositely disposed keysfor engaging two oppositely disposed slotsin the driver. The setback membermoves axially relative to the driverduring dose setting and dose correcting, via the keyand slotinterconnection as shown in. The length of the slotin the drivercan be configured to correspond to a maximum allowed dose to be injected in a single injection. The driveris axially fixed with respect to the pen upper bodyby a transverse wall. An upper surfaceof the flangeabuts the transverse wallof the pen upper body. The spring memberbiases the driver flangeinto contact with the transverse wallthrough the ratchet disk.

As the setback memberrotates with the dose set knobduring injection, the driveris rotated with the setback member. The sloped surfacesandof the driver teethand the ratchet disk teethengage such that the driverrotates relative to the ratchet disk. The spring memberbiases the ratchet diskinto contact with the driver flange, thereby generating a tactile signal and/or clicking noise as the driver teethslip over the ratchet disk teeth. The outwardly extending keysof the ratchet diskare received in the brake member slots, thereby preventing rotation of the ratchet disk.

As described above, the lead screwincludes a plurality of thread segmentsthat are in threaded engagement with threadsof the partially threaded driver, as shown in. Preferably, only a few thread segments are provided at a distal end of the driveras shown in. The lead screwis held non-rotatable with respect to the upper pen bodyby the openingin the brake member. The openinghas a shape corresponding to the shape of the lead screw, which is flattened sides, such that the lead screwis prevented from rotating relative to the brake member. The brake memberis prevented from rotating relative to the pen upper bodydue to the engagement between the slotsin the brake memberand axially extending ribsextending distally from the transverse wall, as shown in. The rotation of the axially fixed driverrotates the lead screwthrough the threaded engagement therebetween, thereby driving the lead screwdistally into the cartridge. The axial movement of the lead screwpushes the stopperdistally into the cartridgeto expel medicament stored therein.

According to an exemplary implementation, during assembly, the driveris inserted in the pen upper bodyfrom the distal end. The brake assemblyincludes the brake member, the spring memberand the ratchet disk, as shown in. The brake assemblyis inserted in the pen upper bodyfrom the distal end. The lead screwis inserted through the openingin the brake memberand through an openingin the driver. The driveris then rotated to draw the lead screwproximally. The slotsin the brake memberrotationally fix the brake memberto the pen upper body. The flattened sidesof the brake member openingreceive the flattened portionsof the lead screw threadsto prevent rotation of the lead screwand limit the lead screw to axial movement.

Exemplary embodiments of braking systems that can be implemented within pen-type injection devices such as those, but without limitation, described above, will now be described with reference to, where analogous components are referenced by similar, non-limiting descriptive, terms.

Referring to, an exemplary embodiment of a braking system includes a Driverrotatably locked to a Ratchet Disk. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Springbiases the Ratchet Disktoward the distal end of the pen. The Ratchet Diskhas sloped surfaces facing the driven direction, and non-sloped surfaces facing the “dial” direction and constitute ratchet teeth. These teethinteract with opposing teethin the Brake Member, which are spaced to correspond with the rotation of one dose of medicament. During dose injection the Ratchet Diskrotates with the Driverand also moves rearward against the Springas sloped teeth surfaces of teethride over the teethof the Brake Member. After rotating to one dose increment the Ratchet Disk“clicks” into the base of the next sloped tooth.

Referring to, an exemplary embodiment of a braking system includes a Ratchet Diskrotatably locked to a Brake Member. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Springbiases the Ratchet Disktoward the proximal end of the Driver. The Ratchet Diskhas sloped surfaces facing the driven direction, and non-sloped surfaces facing the “dial” direction and constitute ratchet teeth. The teethinteract with opposing teethon the Driver, which are spaced to correspond with the rotation of one dose of medicament. During dose injection the Driverrotates, forcing the Ratchet Diskto move axially as the ratchet teeth/slide past each other. After rotating to one dose increment the Ratchet Disk“clicks” into the base of the next sloped tooth.

Referring to, an exemplary embodiment of a braking system includes a Ratchet Diskrotatably locked to a Brake Member. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Springbiases the Ratchet Disktoward the distal end of the Driver. The Ratchet Diskhas sloped surfaces facing the driven direction, and non-sloped surfaces facing the “dial” direction and constitute ratchet teeth. The teethinteract with opposing teethon the Driver, which are spaced to correspond with the rotation of one dose of medicament. During dose injection the Driverrotates, forcing the Ratchet Diskto move axially as the ratchet teeth/slide past each other. After rotating to one dose increment the Ratchet Disk“clicks” into the base of the next sloped tooth.

Referring to, an exemplary embodiment of a braking system includes a Ratchet Diskrotatably locked to a Brake Member. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Ratchet Diskhas flexible ratchet armsthat radiate outward toward the inward facing ratchet teethof the Driver. The Ratchet teethof the driverare spaced to correspond with the rotation of one dose of medicament. During dose injection the Driverrotates, forcing the Ratchet armsto flex inward as the ratchet teethslide past them. After rotating to one dose increment the Ratchet Disk“clicks” into the base of the next sloped tooth.

Referring to, an exemplary embodiment of a braking system includes a Ratchet Diskrotatably locked to a Brake Member. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Driverhas flexible ratchet armsthat radiate inward toward the outward facing ratchet teethof the Ratchet Disk. The Ratchet teethof the Ratchet Diskare spaced to correspond with the rotation of one dose of medicament. During dose injection the Driverrotates, forcing its flexible ratchet armsto flex outward as they slide over the Ratchet teeth. After rotating to one dose increment the Ratchet arms“click” into the base of the next sloped tooth.

Referring to, an exemplary embodiment of a braking system includes a Ratchet Platerotatably locked to a Brake Member. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Ratchet Platehas parabolic waves facing outward toward the Brake Member. The Driverhas sloped surfaces facing the driven direction, and non-sloped surfaces facing the “dial” direction and constitute ratchet teeth. Ratchet teethof the Driver are spaced to correspond with the rotation of one dose of medicament. During dose injection the Driverrotates, forcing the waves of the Ratchet plateto flex to allow the Ratchet teethto rotate past the cavity walls. After rotating to one dose increment the Ratchet teeth“click” into the wall of the next Ratchet plate cavity.

Referring to, an exemplary embodiment of a braking system includes a Driverhaving flexible ratchetarms that radiate outward toward the inward facing ratchet teethof a Brake Member. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Ratchet teethof the Brake Memberare spaced to correspond with the rotation of one dose of medicament. During dose injection the Driverrotates, forcing its flexible ratchet armsto flex inward as they slide over the Ratchet teeth. After rotating to one dose increment the Ratchet arms“click” into the base of the next sloped tooth.

Referring to, an exemplary embodiment of a braking system includes a coil Springpositioned around the head of the Driver. An example of a pen-type injection device implementing such a braking system includes, for example as described above but without limitation and in any combination, other components such as: a button, DSK, setback, and dose stopdisposed in body; flexible spacer, lead screw, cartridgecontaining medicament, cartridge holder(which contains cartridgeand, for example can be removably attached to the bodyinteracting with spacer); and flangedisposed at a distal end of the lead screwto engage a stopperdisposed in the cartridge. The Springis rotatably locked to the Brake Memberwhich is rotatably locked to the Body. The coil Springis oriented to grip the driverand prevent Driverfrom rotating during dialing. If the Driverstarts to rotate backwards the Springtightens around it, preventing it from rotating back. When the driverstarts to rotate in the Injection direction, the springloosens (unwinds) slightly, relieving its grip on the Driverand allowing it to rotate. Clicking during dose injection can be created by a weak clicker (not shown) that is not configured to prevent rotation.